He still doesn't understand a current source? And he calls me ignorant? Wow! Who is the ignorant now?
Oh well, let him go on... he is but one of dozens whose head is bigger than their intellect.
Bye!
Oh well, let him go on... he is but one of dozens whose head is bigger than their intellect.
Bye!
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best to learn from this....Current source - Wikipedia
from rod elliot: Current Sources, Sinks and Mirrors in Audio
college textbooks and there are a lot in the internet described current source with more authority than what we are forced to eat here from Joe...
from rod elliot: Current Sources, Sinks and Mirrors in Audio
college textbooks and there are a lot in the internet described current source with more authority than what we are forced to eat here from Joe...
In software like SoundEasy we can simulate a source impedance by adding a large resistor, even if there is no physical resistor there. I typically use 200 Ohm when I need a CS. Also, Esa uses voltage amplifiers and puts the load (speaker) into the feedback loop. Dave and I have done the same sort of thing. But you need a LOT of feedback to get a high output impedance, but I don't like amps with a lot of feedback (but I have some).
Dave knows this schematic, it has 200+ Ohm output impedance and no physical series resistor:
So it is not incorrect to use infinity to define a perfect current source. This is not about Thevenin, but it is understandable if a newbie has a problem with this, not a self-appointed expert.
On the same topic some might be interested in this:
I asked Esa, after having thought of a number myself, what ratio he would require as a minimum ratio to get the 'current' effect improvement in sound that he claims. He came back with five and that happened to be the same minimum number I had decided, but thinking ten was the aim as that defines a voltage source, to have less than 1dB insertion loss, that points by convention to ten.
To get that without a feedback mechanism is difficult. Not impossible though, ask Nelson Pass.
We then discussed adding a series resistor of five times to a driver/speaker, he showed me a crossover with inbuilt resistors, but he asked me not to reveal them (I have kept my word).
The problem is indeed that it does require many times the voltage swing and there are heavy losses, though minimised in his crossovers.
But again, I don't consider myself in any camp.
And yes, I know what an output impedance is and how to measure it. Probably done that measurement a thousand times.
Cheers, Joe
PS: You also need a LOT of feedback to get a voltage source ultra-low impedance. So zero feedback tends to be "Unity Coupling" as the impedance is similar to the speaker. Lynn told me that the phrase originated in the 1940's with the earliest PP amps, which excluded feedback. My own amplifiers (my design) are in the range 1.5 to 3 Ohm. The 4 Ohm taps are around 1.5 Ohm.
Dave knows this schematic, it has 200+ Ohm output impedance and no physical series resistor:
So it is not incorrect to use infinity to define a perfect current source. This is not about Thevenin, but it is understandable if a newbie has a problem with this, not a self-appointed expert.
On the same topic some might be interested in this:
I asked Esa, after having thought of a number myself, what ratio he would require as a minimum ratio to get the 'current' effect improvement in sound that he claims. He came back with five and that happened to be the same minimum number I had decided, but thinking ten was the aim as that defines a voltage source, to have less than 1dB insertion loss, that points by convention to ten.
To get that without a feedback mechanism is difficult. Not impossible though, ask Nelson Pass.
We then discussed adding a series resistor of five times to a driver/speaker, he showed me a crossover with inbuilt resistors, but he asked me not to reveal them (I have kept my word).
The problem is indeed that it does require many times the voltage swing and there are heavy losses, though minimised in his crossovers.
But again, I don't consider myself in any camp.
And yes, I know what an output impedance is and how to measure it. Probably done that measurement a thousand times.
Cheers, Joe
PS: You also need a LOT of feedback to get a voltage source ultra-low impedance. So zero feedback tends to be "Unity Coupling" as the impedance is similar to the speaker. Lynn told me that the phrase originated in the 1940's with the earliest PP amps, which excluded feedback. My own amplifiers (my design) are in the range 1.5 to 3 Ohm. The 4 Ohm taps are around 1.5 Ohm.
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Tony I agree with you, but losing DF96 I feel almost alone and will not bother anymore.
There is no "voltage" vs "current" way of looking at things, just Joe's fantacy.
@Joe - Since you don't understand even the EE101 basics stick to the stuff you write you have no business criticizing anyone who does.
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Besides interaction with the speaker's impedance could it be the higher output Z thing bringing s glimse of something new to the party. That is what Joe is trying to explore i think.
SE also almost always have monotonically decreasing distortion products. In an SE amp, the hystereous loop does not have to pass thru 0. Often no feedback.
What other things am i missing?
I am interested in the sound. Synergy often brings benefits far in excess of cost. And that is of particular interest to Frugal-Philes™ everywhere.
dave
If you modeled the speaker as ideal (ex. flat impedance, flat frequency response, no distortion, etc), you can make less/no compromise at amplifier design. But nothing ideal in the world.
So, if an amplifier sound good in specific speaker, it doesn't mean sound good in every speaker. But a good amplifier should sound good in many speaker.
Hi Dave,
Well, the discussion Joe always ends up having is in a form that can't be easily understood and often has technical errors making it impossible to prove a point.
It is pointless attempting to discuss anything with Joe, so whatever he might be trying to explore really cannot be understood through his posts.
I'm sure you'll agree that if you are trying to make a point or prove something - anything, you have to at least have your facts correctly presented. Otherwise all is lost.
There is only one thing going on. Repacking observations and trying to deliver something "new". Couple that with technical errors and you have the basis for claims to a new factor previously missed. When you consider just how many people have been studying speakers over the years, both professional and amateur, the only things that are new are mistakes (and those are merely repeated errors from earlier times).
-Chris
Well, the discussion Joe always ends up having is in a form that can't be easily understood and often has technical errors making it impossible to prove a point.
It is pointless attempting to discuss anything with Joe, so whatever he might be trying to explore really cannot be understood through his posts.
I'm sure you'll agree that if you are trying to make a point or prove something - anything, you have to at least have your facts correctly presented. Otherwise all is lost.
Wish-full thinking. Most of the basic science was known in the 1930's and we have added to the knowledge periodically over time. By today, there really isn't any new science to be found. Nothing new to be heard that skilled listeners haven't reported. Even yourself Dave.
There is only one thing going on. Repacking observations and trying to deliver something "new". Couple that with technical errors and you have the basis for claims to a new factor previously missed. When you consider just how many people have been studying speakers over the years, both professional and amateur, the only things that are new are mistakes (and those are merely repeated errors from earlier times).
-Chris
Yet it keeps coming. And the ear/brain side of the equation there is still a lot to be learned.
This isn’t trying to invent new stuff, it is exploring stuff that those before us explored, to look at it with modern eyes and tools but ended up by the wayside because of the drive to push costs down.
dave
Dave,
No. You are now talking about interpretation of how things sound, not what Joe is making errors with.
If you wish to develop the ear/brain relationship, open a thread for that It has nothing to do with the topic of this thread. Nor does all the junk Joe just unleashed here from the BT thread.
-Chris
No. You are now talking about interpretation of how things sound, not what Joe is making errors with.
If you wish to develop the ear/brain relationship, open a thread for that It has nothing to do with the topic of this thread. Nor does all the junk Joe just unleashed here from the BT thread.
-Chris
single ended amps are like cooking your favorite dish..
push-pull amps are like building a bike from the ground up..
Joe, you are rehashing material from the blowtorch threads. If you want to provide the occasional link to the post there, fine. Reposting that material and arguments in this thread isn't allowed and pretty much constitutes thread jacking.
Cease and desist immediately. Continuation will place you in read only mode.
-Chris
ignoring the huge IR losses with a large series resistor (which don't occur with a real CC amplifier or zero loop FB pentode transformer amp) can Hornresp correctly predict the relative interaction effects of high source impedance?
@ Joe - "Because I believe that tube amplifiers have an advantage due to the output transformer providing a better current delivery system."
How about the autotransformers used in McIntosh SS amps? Do they provide a similar advantage in terms of a better current delivery system? One would intuitively think that by raising the output Z from what a typical SS amp provides, this would make the speaker drive more "current like". Some say "The autoformer has a whole lot to do with the sound quality of McIntosh amps".
Does this follow the principle?
How about the autotransformers used in McIntosh SS amps? Do they provide a similar advantage in terms of a better current delivery system? One would intuitively think that by raising the output Z from what a typical SS amp provides, this would make the speaker drive more "current like". Some say "The autoformer has a whole lot to do with the sound quality of McIntosh amps".
Does this follow the principle?
I think that's a remarkably arrogant and intellectually dishonest statement to make.
what a joke!
It largely ignores the giants of the past, proper university research, well known background work in psycho-acoustics and the drive to make modern living and working spaces more acoustic friendly, - and they don't date from yesterday.
The ability successfully to model acoustic structures and performance in architecture is extremely well known, to the extent it was used in the outdoor music festival "Roque d'Anteron".
There can be NO MORE challenging environment than an outdoor event space, but to get the spread of +/- 2dB SPL over an entire audience is nothing short of miraculous, - using NO PA or sound reinforcement equipment whatsoever.
There have been extended studies of noise exposure on orchestral musicians, research promoted by the French CNRS, and suddenly we have some nobody pops out of nowhere promoting theories claiming he has something wildly new and revolutionary.
yea get a life! 🙄
Another one I count on one hand that ACTUALLY knows what he's on about.
The USSR made some excellent engineers, which is why they very nearly beat the USA to land on the moon.
If you have ever flown on a TU154B, you would understand they had to make stuff so brick built they could just about land it anywhere,- including on a too short disused airfield covered in trees and shrubs, and then not kill anyone. 😱
Any increase in the series impedance flattens the current phase angle and gets you down that road. As for McIntosh, hadn't thought about that, but maybe.
Hi Fred,
Not quite sure what you mean by "relative interaction", but setting Rg to a high value will in effect give you a constant current source amplifier.
Try comparing the results obtained using the input parameter values shown in Attachment 1 against those obtained using the Maximum SPL tool with the setting shown in Attachment 2 (in effect specifying a constant current source of 1 amp). You should find that the results are almost identical. The very small difference is due to the current using Eg = 1000 volts and Rg = 1000 ohms being slightly less than the exact 1 amp used by the Maximum SPL tool.
Kind regards,
David
Attachments
Thanks for answering my reply, Joe.
When someone posts something like "it's the current not the voltage" and I find it interesting, I try to piece together a constellation of evidence to support/refute such a belief.
Like so many, I've always been interested in why amplifiers sound different and what is it about tube amps that makes them as attractive. All the horn-locking aside, I've learned some good stuff from this thread and it's inspired some further thinking on my part about "tubes" and "their sound".
I feel confident in my decision to purchase a low Z output amp for the woofers in my bi-amped speaker project and I've learned that I can always futz a little with the driver Q by using a resistor. It doesnt have to sell...
I feel confident in using / pursuing a higher Z output amp for the rest of the frequency range. It's something I've long suspected and its good to have those suspicions ratified by anothers thinking on the subject.
Of course we all could be wrong, but I'm not about to go buy myself an Adcom GFA amplifier to run my FR driver. I think I'll go down that other road successfully -
When someone posts something like "it's the current not the voltage" and I find it interesting, I try to piece together a constellation of evidence to support/refute such a belief.
Like so many, I've always been interested in why amplifiers sound different and what is it about tube amps that makes them as attractive. All the horn-locking aside, I've learned some good stuff from this thread and it's inspired some further thinking on my part about "tubes" and "their sound".
I feel confident in my decision to purchase a low Z output amp for the woofers in my bi-amped speaker project and I've learned that I can always futz a little with the driver Q by using a resistor. It doesnt have to sell...
I feel confident in using / pursuing a higher Z output amp for the rest of the frequency range. It's something I've long suspected and its good to have those suspicions ratified by anothers thinking on the subject.
Of course we all could be wrong, but I'm not about to go buy myself an Adcom GFA amplifier to run my FR driver. I think I'll go down that other road successfully -
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